Utricular and Saccular Volumetry in Human Temporal Bones

Igarashi, Makoto; O‐Uchi, Toshiaki; Isago, Hiroaki; Wright, William K.

doi:10.3109/00016488309130918

Cited by 37 publications

(20 citation statements)

References 17 publications

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“…We therefore applied the model to this species to generate speci®c results for discussion. The gross morphology of the system is remarkably preserved across species to such an extent that the toad®sh labyrinth is quite similar to that of primates and human (Igarashi 1967;Igarashi et al 1981, Igarashi et al 1983Ghanem et al 1998). Prime directions and model predictions will, of course, vary for other species, but the concepts should be universal across a very broad spectrum of animals.…”

Section: Model Geometrymentioning

confidence: 94%

Directional coding of three-dimensional movements by the vestibular semicircular canals

Rabbitt

1999

Biological Cybernetics

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A morphologically descriptive mathematical model was developed to study the role of labyrinthine geometry in determining sensitivities of each semicircular canal to angular motion stimuli in three-dimensional (3D) space. For this, equations describing viscous flow of the endolymph and poro-elastic response of the cupulae were coupled together and solved within a 3D reconstructed geometry. Results predict the existence of prime rotational directions about which the labyrinth resolves 3D angular movements into separate vectorial components. The components are predicted to be transmitted to the brain separately, one coded by each canal nerve. Prime directions predicted by the model are non-orthogonal, distinct from the anatomical canal planes, and distinct from the directions of rotation which elicit maximal responses of individual canal nerves. They occur for each canal along the intersection of the two null planes defined by its sister canals. Hence, rotation about a prime direction excites only one canal nerve. This contrasts the situation for rotations about anatomical canal planes, or about maximal response directions, where the model predicts activation of multiple canal nerves. The prime directions are sensitive to labyrinthine morphology and, hence, are predicted to vary between species and, to a lesser extent, vary between individual animals. Prime directions were estimated in the present work using a mathematical model, but could be determined experimentally based on the directional sensitivities of individual canal nerves. The model also predicts the existence of dominant eigenmodes and time constants associated with rotation in each of the prime directions. Results may have implications regarding the central representation of angular head movements in space as well as the neuronal mappings between three-canal afferent inputs and motor outputs.

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Section: Model Geometrymentioning

confidence: 94%

Directional coding of three-dimensional movements by the vestibular semicircular canals

Rabbitt

1999

Biological Cybernetics

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“…Using measurements from the plastic mold, histologic cross sections, and macrosections, as well as average figures given in various anatomy books and published articles, [1][2][3][4][5][6][7][8][9] we calculated the volume of the components of the bony labyrinth. The bony labyrinth is divided into 3 semicircular canals, 3 ampullae, a vestibule, and a cochlea (Fig 1).…”

Section: Methodsmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9] We divided the endolymphatic spaces into 3 semicircular canals and ampullae, I utricle, I saccule, and a cochlear duct. The results of these calculations are included in the The mathematical method using geometric formulae and measurements from anatomy books and histologic sections can provide only approximate figures.…”

Section: Methodsmentioning

confidence: 99%

“…We became interested in knowing the actual volumes of the perilymphatic and endolymphatic spaces of the inner ear structures, and whether it is possible to recognize such structures as the saccule, utricle, and membranous semicircular canals on MRI. In a search of the literature, including anatomy textbooks, [1][2][3][4][5][6][7][8][9] we found only I report I with more than isolated, incomplete data on the volumes of these structures.…”

Section: Introductionmentioning

confidence: 99%

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Inner Ear Fluid Volumes and the Resolving Power of Magnetic Resonance Imaging: Can it Differentiate Endolymphatic Structures?

Buckingham¹,

Valvassori²

2001

Ann Otol Rhinol Laryngol

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Magnetic resonance imaging (MRI) can accurately recognize minute volumes as small as I mm'. The volumes of the utricle and saccule of the inner ear are within the resolving power of MRI, but these structures cannot be recognized because the endolymph and perilymph signals are identical. To clarify the interpretation and description of inner ear structures on MRI, we measured and calculated the volumes of the perilymphatic and endolymphatic spaces of the human ear. We found the total volume of the bony labyrinth to be approximately 192.5 mm' (endolymph, 34.0 mm-'; perilymph, 158.5 mm').KEY WORDS -inner ear volume, labyrinth volume, magnetic resonance imaging.

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“…Isolated measures of some of these dimensions are available in some species, usually from fixed, decalcified, serial sectioned material (Clark, 1973;Cummins, 1925;Curthoys et al, 1977a, 19776; Fernandez & Valentinuzzi, 1%8; Gray, 1907;Igarashi, 1%7;Igarashi et al, 1981Igarashi et al, , 1983; Jones & Spells, 1963). Igarashi et al (1981Igarashi et al ( , 1983 recently measured the volumes of various endolymphatic spaces and the length of the lateral membranous canal duct in the squirrel monkey and human. However, in their studies, several important parameters, such as fluid flow path length and contained area, were not reported.…”

mentioning

confidence: 98%

Dimensions of the Horizontal Semicircular Duct, Ampulla and Utricle in Rat and Guinea Pig

Curthoys

Oman

1986

Acta Oto-Laryngologica

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The dimensions of the membranous labyrinth partly determine the mechanical operation of the semicircular canal system. This study provides, for the first time, extensive measures in individual specimens of the sizes, cross-sectional shapes and areas of the horizontal semicircular duct, ampulla and utricle in the rat and the guinea pig. The membranous labyrinths were fixed in Karnovsky's fixative, exposed, photographed, sectioned, oriented perpendicular to the line of sight and then measured using a calibrated graticule in the eye piece of an operating microscope. As well as the expected size differences between these species, there are major differences in the shape of the utricle.

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Utricular and Saccular Volumetry in Human Temporal Bones

Cited by 37 publications

References 17 publications

Directional coding of three-dimensional movements by the vestibular semicircular canals

Directional coding of three-dimensional movements by the vestibular semicircular canals

Inner Ear Fluid Volumes and the Resolving Power of Magnetic Resonance Imaging: Can it Differentiate Endolymphatic Structures?

Dimensions of the Horizontal Semicircular Duct, Ampulla and Utricle in Rat and Guinea Pig

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